1. Field of the Invention
The present invention relates to bill acceptor technology and more particularly, to a bill acceptor with bill passage anti-light pollution arrangement, which has privacy filters installed in the light path of the bill-receiving unit thereof to reduce light pollution, avoiding errors and faults and enhancing detection accuracy and reliability.
2. Description of the Related Art
Following fast development of modern technology, convenience and rapidness have become important demands in our modern daily life. Nowadays, different automatic vending machines, card dispensers, auto teller machines, ticket machines and bill exchange machines are used everywhere to sell different products and/or to provide different services without serviceman. These machines are highly appreciated for the advantage of saving much labor and bringing convenience to people.
Further, commercial automatic vending machines, auto teller machines and other consumer systems may be equipped with a bill acceptor for receiving paper money. To avoid direct loss due to counterfeiting and to avoid inadvertently passing counterfeit valuable papers to consumers, a bill acceptor has recognition means to recognize the authenticity of a valuable paper before receiving it. However, the bill passage of a bill acceptor is specifically designed for a particular valuable paper of one specific width. Because different valuable papers issued from different countries have different sizes (length, width and thickness) and different anti-counterfeit characteristics at different locations. A valuable paper that is inserted into a bill acceptor must be kept in accurate alignment with the recognition device so that the recognition device can accurate recognize the anti-counterfeit characteristics. If a valuable paper is inserted into a bill acceptor in an offset manner, the recognition device of the bill acceptor may reject the valuable paper due to a recognition error. In this case, the user must insert the valuable paper again, causing inconvenience.
Further, during the operation of a recognition device of a bill acceptor to validate the authenticity of an inserted valuable paper, a light emitter (for example, light-emitting diode) of the recognition device emits light through a lens set and the inserted valuable paper toward a light sensor. The light sensor determines the authenticity of the valuable paper by measuring the energy of the light that passes through the inserted valuable paper. Subject to the anti-counterfeit characteristics (watermark, seal, hidden barcode or laser tag) and material thickness, the authenticity and face value of the inserted valuable paper can be accurately validated.
However, during validation operation of a recognition device of a bill acceptor, sunlight or external luminous light or flashing light may pass through the bill slot of the face panel into the internal bill passage of the bill acceptor to fall upon the dust cover and the lens set of the recognition device to interfere with the light being emitted by the light emitter toward the light sensor, resulting in a false detection or detection error. The dust cover has wear-resistant, dustproof and anti-stain characteristics, but it cannot filtrate external light rays to eliminate light pollution. When a light pollution occurs, the validation accuracy will be affected. If an inserted valuable paper cannot be validated and is rejected, the user shall have to insert the valuable paper into the bill slot again, causing inconvenience.
Therefore, it is desirable to provide a bill acceptor that filtrates light pollution, avoiding errors and faults.